const s1 = Symbol('111');
const s2 = Symbol('111');
console.log(s1 == s2);
const secretKey = Symbol('secret');
console.log(secretKey,'///')
// 多人协作中 Why Symbol？
// 动态 不太安全？
// key string 类型 | Symbol 
const a = "ecut";
const user = {
    [secretKey]:'111222',
    name:'11',
    email:'11@163.com',
    "a": 123,
    [a]:456456
}
console.log(user.ecut,user[a]);
user.email = '11@qq.com';